Following the accident at the Fukushima Daiichi Nuclear Power Plant, some kind of unmanned aerial vehicles (UAVs) have been used to collect environmental radiation data. The Japan Atomic Energy Agency has been developed methods for analyzing radiation measurements taken by a small multirotor UAV. In the conventional method, count rate was converted to the air dose rate using a simple parameter. Therefore, such a conversion of the air dose rate using the conventional method is difficult in an area where the distribution of air dose rate is heterogeneous, or the terrain is complex. The goal of this study was to apply the inverse radiation method, which is used in medical applications such as positron emission tomography, for environmental radiation measurement. Basic algorithm was established for conversion from count rate to air dose rate in considering of topographic data. The algorithm was applied to real radiation data obtained by a UAV, and its accuracy was evaluated by comparing that data with ground measurement data. As compared with conventional methods, our algorithm was demonstrated to achieve a more accurate estimation of the air dose rate on the ground.
{"title":"Development of analysis method for airborne radiation monitoring using the inverse problem solutions","authors":"M. Sasaki, Azusa Ishizaki, Y. Sanada","doi":"10.15669/PNST.6.63","DOIUrl":"https://doi.org/10.15669/PNST.6.63","url":null,"abstract":"Following the accident at the Fukushima Daiichi Nuclear Power Plant, some kind of unmanned aerial vehicles (UAVs) have been used to collect environmental radiation data. The Japan Atomic Energy Agency has been developed methods for analyzing radiation measurements taken by a small multirotor UAV. In the conventional method, count rate was converted to the air dose rate using a simple parameter. Therefore, such a conversion of the air dose rate using the conventional method is difficult in an area where the distribution of air dose rate is heterogeneous, or the terrain is complex. The goal of this study was to apply the inverse radiation method, which is used in medical applications such as positron emission tomography, for environmental radiation measurement. Basic algorithm was established for conversion from count rate to air dose rate in considering of topographic data. The algorithm was applied to real radiation data obtained by a UAV, and its accuracy was evaluated by comparing that data with ground measurement data. As compared with conventional methods, our algorithm was demonstrated to achieve a more accurate estimation of the air dose rate on the ground.","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82379564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Nakajima, T. Batpurev, W. M. Chan, F. Dokaku, K. Fushimi, K. Kanagawa, S. Katagiri, K. Kawasaki, B. T. Khai, H. Kino, E. Kinoshita, T. Kishimoto, R. Hazama, H. Hiraoka, Daiki Hiyama, T. Iida, M. Ishikawa, Xiaolong Li, T. Maeda, K. Matsuoka, M. Moser, M. Nomachi, I. Ogawa, T. Ohata, Hiroyoshi Sato, K. Shamoto, M. Shimada, M. Shokati, N. Takahashi, Y. Takemoto, Y. Takihira, Y. Tamagawa, M. Tozawa, K. Teranishi, K. Tetsuno, V. Trang, M. Tsuzuki, S. Umehara, Wei Wang, S. Yoshida, N. Yotsunaga
In the CANDLES experiment aiming to search for the very rare neutrino-less double beta decays (0νββ) using 48Ca, we introduced a new shielding system for high energy γ-rays from neutron captures in massive materials near the detector, in addition to the background reduction for 232Th decays in the 0νββ target of CaF2 crystals. The method of background reduction and the performance of newly installed shielding system are described.
{"title":"Upgrading of shielding for rare decay search in CANDLES","authors":"K. Nakajima, T. Batpurev, W. M. Chan, F. Dokaku, K. Fushimi, K. Kanagawa, S. Katagiri, K. Kawasaki, B. T. Khai, H. Kino, E. Kinoshita, T. Kishimoto, R. Hazama, H. Hiraoka, Daiki Hiyama, T. Iida, M. Ishikawa, Xiaolong Li, T. Maeda, K. Matsuoka, M. Moser, M. Nomachi, I. Ogawa, T. Ohata, Hiroyoshi Sato, K. Shamoto, M. Shimada, M. Shokati, N. Takahashi, Y. Takemoto, Y. Takihira, Y. Tamagawa, M. Tozawa, K. Teranishi, K. Tetsuno, V. Trang, M. Tsuzuki, S. Umehara, Wei Wang, S. Yoshida, N. Yotsunaga","doi":"10.15669/PNST.6.144","DOIUrl":"https://doi.org/10.15669/PNST.6.144","url":null,"abstract":"In the CANDLES experiment aiming to search for the very rare neutrino-less double beta decays (0νββ) using 48Ca, we introduced a new shielding system for high energy γ-rays from neutron captures in massive materials near the detector, in addition to the background reduction for 232Th decays in the 0νββ target of CaF2 crystals. The method of background reduction and the performance of newly installed shielding system are described.","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82516593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kenichi Watanabe, Tomoaki Mizukoshi, A. Yamazaki, S. Yoshihashi, A. Uritani, T. Iguchi, Tomohiro Ogata, T. Muramatsu, Tetsuro Matsumoto, A. Masuda
{"title":"Response evaluation of Onion-like single Bonner sphere neutron spectrometer using TRUST Eu:LiCAF scintillator","authors":"Kenichi Watanabe, Tomoaki Mizukoshi, A. Yamazaki, S. Yoshihashi, A. Uritani, T. Iguchi, Tomohiro Ogata, T. Muramatsu, Tetsuro Matsumoto, A. Masuda","doi":"10.15669/PNST.6.122","DOIUrl":"https://doi.org/10.15669/PNST.6.122","url":null,"abstract":"","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78973385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We measured activation cross sections of aluminum for 0.4, 1.3, 2.2, and 3.0 GeV protons at J-PARC to obtain basic data for nuclear design of beam windows as the test experiment. It was found that data with higher accuracy than current ones will be measured by using precise beam controls and highly accurate beam monitoring. We compared the experimental results, the evaluated data (JENDL-HE/2007), and calculation results with several intra-nuclear cascade models in PHITS. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated by about 40%, which could come from the evaporation model (GEM) included in PHITS code. It was found that the calculations with original GEM code show good agreement with the experimental data.
{"title":"Measurement of activation cross sections of aluminum for protons with energies between 0.4 GeV and 3.0 GeV at J-PARC","authors":"H. Matsuda, S. Meigo, H. Iwamoto","doi":"10.15669/PNST.6.171","DOIUrl":"https://doi.org/10.15669/PNST.6.171","url":null,"abstract":"We measured activation cross sections of aluminum for 0.4, 1.3, 2.2, and 3.0 GeV protons at J-PARC to obtain basic data for nuclear design of beam windows as the test experiment. It was found that data with higher accuracy than current ones will be measured by using precise beam controls and highly accurate beam monitoring. We compared the experimental results, the evaluated data (JENDL-HE/2007), and calculation results with several intra-nuclear cascade models in PHITS. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated by about 40%, which could come from the evaporation model (GEM) included in PHITS code. It was found that the calculations with original GEM code show good agreement with the experimental data.","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91478902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to confirm accuracy of radiation transport codes, a neutron streaming experiment was conducted. An iron-polyethylene multi-layer shielding assembly was fabricated, and neutron dose distribution was measured. The shielding assembly has a three-legged rectangular duct of which the total length is 750 mm. An encapsulated Cf-252 source was set in front of the entrance of the duct to irradiate the neutron detector, and the dose along the duct was measured by the bubble detectors placed inside. The neutron dose was also calculated by the Monte Carlo codes, PHITS and MCNP5, using various nuclear data libraries, JENDL-4.0, ENDF/B-VII.1 and JEFF-3.1. The difference depending on nuclear libraries is not significant. The calculations agree well with the experiments in both cases where PHITS and MCNP5 are used.
{"title":"Experiment and analysis of neutron streaming in iron-polyethylene multi-layer shielding assembly","authors":"S. Ohnishi, Koichi Okuno, A. Konnai, K. Sawada","doi":"10.15669/PNST.6.139","DOIUrl":"https://doi.org/10.15669/PNST.6.139","url":null,"abstract":"In order to confirm accuracy of radiation transport codes, a neutron streaming experiment was conducted. An iron-polyethylene multi-layer shielding assembly was fabricated, and neutron dose distribution was measured. The shielding assembly has a three-legged rectangular duct of which the total length is 750 mm. An encapsulated Cf-252 source was set in front of the entrance of the duct to irradiate the neutron detector, and the dose along the duct was measured by the bubble detectors placed inside. The neutron dose was also calculated by the Monte Carlo codes, PHITS and MCNP5, using various nuclear data libraries, JENDL-4.0, ENDF/B-VII.1 and JEFF-3.1. The difference depending on nuclear libraries is not significant. The calculations agree well with the experiments in both cases where PHITS and MCNP5 are used.","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85192932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shohei Iwai, F. Nobuhara, Masahiro Tanaka, Naoki Nagasawa
{"title":"Investigation of activation range for self-shielded PET cyclotron","authors":"Shohei Iwai, F. Nobuhara, Masahiro Tanaka, Naoki Nagasawa","doi":"10.15669/PNST.6.217","DOIUrl":"https://doi.org/10.15669/PNST.6.217","url":null,"abstract":"","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"46 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83404864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Decommissioning wastes generated from decommissioning of a nuclear power plant are mainly comprised of metal wastes. These metal wastes are considered to be possible of clearance by appropriate management. Accordingly, this study is carried out to assess the possibility of clearance from the viewpoint of worker safety during the clearance of metal wastes with the aim of reducing the disposal amount of radioactive metal wastes during the decommissioning of a nuclear power plant. The assessment targets were the Boron Recovery Tank pipes and pressurizer, and the RESRAD-RECYCLE computer code was used to assess the radiological risk of each scenario. The assessment results showed that the BRT pipes met the permissible radiation dosage for clearance and the pressurizer met the permissible radiation dosage for clearance after 23 years in case of the decontamination factor of 1,000 and after 5 years in case of the decontamination factor of 10,000, respectively.
{"title":"A study on the possibility of clearance for radioactive metal wastes from decommissioning of nuclear power plants in Korea","authors":"J. Song, Dong-Min Kim, Sang Heon Lee","doi":"10.15669/PNST.6.52","DOIUrl":"https://doi.org/10.15669/PNST.6.52","url":null,"abstract":"Decommissioning wastes generated from decommissioning of a nuclear power plant are mainly comprised of metal wastes. These metal wastes are considered to be possible of clearance by appropriate management. Accordingly, this study is carried out to assess the possibility of clearance from the viewpoint of worker safety during the clearance of metal wastes with the aim of reducing the disposal amount of radioactive metal wastes during the decommissioning of a nuclear power plant. The assessment targets were the Boron Recovery Tank pipes and pressurizer, and the RESRAD-RECYCLE computer code was used to assess the radiological risk of each scenario. The assessment results showed that the BRT pipes met the permissible radiation dosage for clearance and the pressurizer met the permissible radiation dosage for clearance after 23 years in case of the decontamination factor of 1,000 and after 5 years in case of the decontamination factor of 10,000, respectively.","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79334550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Nishitani, K. Ogawa, Hiroki Kawase, N. Pu, T. Ozaki, M. Isobe
On the Large Helical Device (LHD), deuterium plasma experiments began in March 2017. In the plasma control, plasma heating and diagnostic systems, radiation sensitive components such as a programmable logic controller (PLC) and CCD sensors are commonly used. Three-dimensional distributions of neutron and gamma-ray in the LHD experimental building have been calculated by Monte Carlo code MCNP6 with the nuclear data library of ENDF B-VII.1 to prove the precise information on the radiation field and to introduce a countermeasure to the radiation. The total neutron flux in the torus hall of LHD is ~109 n/cm2•s for the maximum neutron yield shot. The total neutron and gamma-ray fluxes in the basement are 1-2 order smaller than those in the torus hall, which is due to the streaming through penetrations in the floor concrete slab. The shielding design for the compact neutral particle analyzer (CNPA) is also carried out. It is found that 10% borated polyethylene thicker than 15 cm is necessary for the shield in all directions.
{"title":"Monte Carlo calculation of the neutron and gamma-ray distributions inside the LHD experimental building and shielding design for diagnostics","authors":"T. Nishitani, K. Ogawa, Hiroki Kawase, N. Pu, T. Ozaki, M. Isobe","doi":"10.15669/PNST.6.48","DOIUrl":"https://doi.org/10.15669/PNST.6.48","url":null,"abstract":"On the Large Helical Device (LHD), deuterium plasma experiments began in March 2017. In the plasma control, plasma heating and diagnostic systems, radiation sensitive components such as a programmable logic controller (PLC) and CCD sensors are commonly used. Three-dimensional distributions of neutron and gamma-ray in the LHD experimental building have been calculated by Monte Carlo code MCNP6 with the nuclear data library of ENDF B-VII.1 to prove the precise information on the radiation field and to introduce a countermeasure to the radiation. The total neutron flux in the torus hall of LHD is ~109 n/cm2•s for the maximum neutron yield shot. The total neutron and gamma-ray fluxes in the basement are 1-2 order smaller than those in the torus hall, which is due to the streaming through penetrations in the floor concrete slab. The shielding design for the compact neutral particle analyzer (CNPA) is also carried out. It is found that 10% borated polyethylene thicker than 15 cm is necessary for the shield in all directions.","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80578773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Tanimura, S. Nishino, H. Yoshitomi, M. Kowatari, T. Oishi
{"title":"Characteristics of commercially available CdZnTe detector as gamma-ray spectrometer under severe nuclear accident","authors":"Y. Tanimura, S. Nishino, H. Yoshitomi, M. Kowatari, T. Oishi","doi":"10.15669/PNST.6.134","DOIUrl":"https://doi.org/10.15669/PNST.6.134","url":null,"abstract":"","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86328226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nazia Neelam Shehzadi, J. Chung, In Jung Kim, B. Kim, C. Yi
The radio-photoluminescence glass dosimetry test was carried out carefully. For the test, a therapy level Co-60 gamma-ray beam was used for the irradiation of the known doses to the dosimeters with the standard uncertainty of 0.7 % (k = 1). A weak negative correlation between mass and response of the glass dosimeter was found with Pearson’s correlation coefficient -0.27, -0.29, -0.29, -0.27 and -0.26 for glass dosimeters irradiated at 1, 3, 5, 7 and 9 Gy radiation doses, respectively. It has been confirmed that the statistical uncertainty of the radio-photoluminescence glass dosimetry can be obtained within 1 % from the repeatability test.
{"title":"Preliminary study on precision dosimetry using radio-photoluminescent glass dosimeters for future use in radiotherapy","authors":"Nazia Neelam Shehzadi, J. Chung, In Jung Kim, B. Kim, C. Yi","doi":"10.15669/PNST.6.221","DOIUrl":"https://doi.org/10.15669/PNST.6.221","url":null,"abstract":"The radio-photoluminescence glass dosimetry test was carried out carefully. For the test, a therapy level Co-60 gamma-ray beam was used for the irradiation of the known doses to the dosimeters with the standard uncertainty of 0.7 % (k = 1). A weak negative correlation between mass and response of the glass dosimeter was found with Pearson’s correlation coefficient -0.27, -0.29, -0.29, -0.27 and -0.26 for glass dosimeters irradiated at 1, 3, 5, 7 and 9 Gy radiation doses, respectively. It has been confirmed that the statistical uncertainty of the radio-photoluminescence glass dosimetry can be obtained within 1 % from the repeatability test.","PeriodicalId":20706,"journal":{"name":"Progress in Nuclear Science and Technology","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91544581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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